62
graph with the left side of the chart to determine that the
range configuration for the CO2sensor should be 1800
ppm. The EconoMi$er IV controller will output the 6.7
volts from the CO2sensor to the actuator when the CO2
concentration in the space is at 1100 ppm. The DCV
setpoint may be left at 2 volts since the CO2sensor
voltage will be ignored by the EconoMi$er IV controller
until it rises above the 3.6 volt setting of the minimum
positionpotentiometer.
Once the fully occupied damper position has been
determined, set the maximum damper demand control
ventilationpotentiometer to this position. Do not set to the
maximum position asthis can result in over-ventilation to
the space and potentialhigh humidity levels.
CO2Sensor Configuration
The CO2sensor has preset standard voltage settings that
can be selected anytime after the sensor is powered up.
(See Table28. )
Use setting1 or 2 for Carrier equipment. (See Table 28.)
1. Press Cle ar and Mode buttons. Hold at least 5
seconds until the sensor enters the Edit mode.
2. Press Mode twice. TheSTDSET Menu will appear.
Table28 – EconoMi$er IV SensorUsage
APPLICATION
ECONOMI$ER IV WITH OUTDOOR AIR DRY
BULBSENSOR
AccessoriesRequired
Outdoor Air
DryB ulb
None.T he outdoor air dry bulb sensor is
factory installed.
Differential
DryB ulb CRTEMPSN002A00*
Single Enthalpy HH57AC078
Differential
Enthalpy HH57AC078 and CRENTDIF004A00*
CO2forDCV
Controlusing a
Wall-Mounted
CO2Sensor
33ZCSENCO2
CO2forDCV
Controlusing a
Duct-Mounted
CO2Sensor
33ZCSENCO2† and
33ZCASPCO2**
O
RCRCBDIOX005A00††
* CRENTDIF004A00and CRTEMPSN002A00 accessories are
usedon many different base units. As such, these kitsmay
containp arts that will not be needed for installation.
† 33ZCSENCO2is an accessoryCO2sensor.
** 33ZCASPCO2 is an accessory aspirator box required for duct-
mountedapplications.
†† CRCBDIOX005A00 is an accessory that contains both
33ZCSENCO2 and 33ZCASPCO2 accessories.
3. Use the Up/Down button to select the preset
number. (See Table28.)
4. Press Enter to lock in the selection.
5. Press Mode to exit and resume normal operation.
The custom settings of the CO2sensor can be changed
anytime after the sensor is energized. Follow the steps
below to change the non-standard settings:
1. Press Cle ar and Mode buttons. Hold at least 5
seconds until the sensor enters the Edit mode.
2. Press Mode twice. TheSTDSET Menu will appear.
3. Use the Up/Down button to toggle to the NONSTD
menu and pressEnter.
4. Use the Up/Down button to toggle through each of
the nine variables, starting with Altitude, until the
desiredsetting is reached.
5. Press Mode to move through the variables.
6. Press Enter to lock in the selection, then press Mode
to continue to the nextvariable.
Dehumidificationof Fresh Air with DCV (Demand
ControlledVentilation)Control
If normal rooftop heating and cooling operation is not
adequate for the outdoor humidity level, an e nergy
recovery unit and/or a dehumidification option should be
considered.
EconoMi$er IV Preparation
This procedure is used to prepare the EconoMi$er IV for
troubleshooting. No troubleshooting or testing is done by
performing the following procedure.
NOTE: This procedure requires a 9--v battery, 1.2
kilo--ohmresistor, and a 5.6 kil o--ohm resistor which are
not supplied with the EconoMi$er IV.
IMPORTANT: Be sure to record the positions of all
potentiometers before starting troubleshooting.
1. Disconnect power at TR and TR1. All LEDs should
be off. Exhaust fan contacts should be open.
2. Disconnect device at P and P1.
3. Jumper P to P1.
4. Disconnect wires at T and T1. Place 5.6 kilo--ohm
resistor across T and T1.
5. Jumper TR to 1.
6. Jumper TR to N.
7. If connected, remove sensor from terminals SO and +.
Connect 1.2 kilo--ohm 4074EJM checkout resistor
acrossterminals SO and +.
8. Put 620--ohmresistor a cross terminals SR and +.
9. Set minimum position, DCV setpoint, and exhaust po-
tentiometers fully CCW (counterclockwise).
10. Set DCVmaximum position potentiometer fully CW
(clockwise).
11. Set enthalpy potentiometerto D.
12. Apply power (24 vac) to terminals TR and TR1.
Differential Enthalpy
Tocheck differential enthalpy:
1. Make sure EconoMi$er IV preparation procedure has
been performed.
2. Place 620--ohm resistor across SO and +.
3. Place 1.2 kilo--ohm resistor across SR and +. The
Free Cool LED shouldbe lit.
4. Remove 620--ohmresistor across SO and +. The Free
Cool LED should turn off.
5. Return EconoMi$er IV settings and wiring to normal
after completing troubleshooting.
48TC